کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1390960 | 983172 | 2006 | 7 صفحه PDF | دانلود رایگان |
The stereochemical outcome of glycosylation reactions with model thioglycosides and selenoglycosides proved to be dependent on the source of promoter iodonium ion, with iodine giving different results to N-iodosuccinimide (NIS) alone or N-iodosuccinimide/trimethylsilyltrifluoromethanesulfonate (NIS/TMSOTf). In contrast to armed thioglycosides, which anomerise, and disarmed thioglycosides, which do not react, both armed and disarmed selenoglycosides give rise to the corresponding glycosyl iodides when reacted with iodine. Further, whilst the single electron transfer agent DDQ alone is an ineffective promoter, in combination with iodine it produces better acetonitrile-assisted β-stereoselectivity with both thioglycosides and selenoglycosides than does tris(4-bromophenyl)aminium hexachloroantimonate (BAHA).
Figure optionsDownload as PowerPoint slide
Journal: Carbohydrate Research - Volume 341, Issue 10, 24 July 2006, Pages 1391–1397